Chain tightening device



2 Sheets-Sheet l .3v h @QQ uw mw mw Dec. 12, G, M BURNETT CHAIN TIGHTENING DEVICE Filed Aug. 19, 1949 Dec. 12, 1950 G. M. BURNETT CHAIN TIGHTENING DEVICE 2 Sheets-Sheet 2 Filed Aug. 19, 1949 Patented Dec. 12, 1 950 UNITED STATES PATENT OFFICE CHAIN TGHTENN'G DEVICE Goldie M. Burnett, Sweetwater, Tex., assigner of oneehalf to Roy L. Burnett, Sweetwater, Tex.

Application August 19, 194.9, Serial No. 111,203

5 Claims. l

This invention relates to a device for use in tightening a sprocket chain for taking up or shortening the chain, replacing a broken link or repairing a broken chain.

More particularly, it is an aim of the present invention to provide a device capable 4of being manually operated for tightening a chain and having hook means for holding spaced links of the chain after tightening to prevent said links from moving away from one another so that a broken chain can be repaired or a chain may be shortened.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, illustrating presently preferred embodiment thereof, and wherein:

Figure l is a side elevational view showing the device in an initially applied position engaging a sprocket chain;

Figure 2 is a top plan view of the device with the lever element thereof removed;

Figure 3 is a longitudinal sectional View of the device in an applied position and as it will appear after the end portions of a chain have been drawn together thereby;

Figure 4 is an enlarged longitudinal sectional view taken substantially along a plane as indicated by the line 5 4 of Figure 3;

Figure 5 is a cross sectional view taken substantially along a plane as indicated by the line 5-5 of Figure 3, and

Figure 6 is a horizontal sectional View taken substantially along a plane as indicated by the line 6--6 of Figure 3.

Referring more specifically to the drawings, the sprocket chain tightening device in its entirety is designated generally 'I and includes a housing or body member, designated generally 8 formed of corresponding side walls 9 which are connected adjacent to corresponding ends thereof by a short top wall it) and a somewhat longer bottom wall II which walls I and H combine with complementary portions of the side walls 9 to form a hook shank receiving housing I 2. The walls 9 are connected adjacent to but spaced from their opposite ends by a transverse wall I3.

A chain engaging hook I4 is provided with an elongated shank i of rectangular cross section which is reciprocally disposed in the shank receiving housing I2 of the body 8 and with the hook disposed beyond said end of the body and extending downwardly therefrom. 'Ihe shank I5 is slidably disposed in the housing I2. Aclamping bar It is pivotally mounted in the 2 body e at one end 'thereof on a pin li which extends between the side walls 9 and is disposed inwardly of the top wall i9 and extends from its pivoted end Il toward said wall le and norlnally rests upon a portion of the upper surface of the hook shank. it. A pin or shaft i8 entends through the side walls il, above and adjacent the free end or the clamping member le `and is jourf naled in said side walls and has a lever l iiried f to one exposed end thereof. A cam or eccentric '2t is secured to the shaft it between the side walls S to bear on the clamping 'member it when the shaft is rotated to displace the cani or eccentric 2U downwardly.

The end portions of the side walls 9, beyond the transverse wall i3 are provided with 'aligned openings for receiving a pin 2l which extends through an opening '22 in the 'shank end of a hook 2t, which shank end 'is disposed in the space between said side wall portions 9 and beyond the transverse wall I3. rEhe hook portion 2li oi the hook 23 is laterally off-set with respect :to the plane' oi the hooi: shank and opens lai;`i-

era'lly with respect to the plane of the hook shank and the plane of the body member 8, as best illustrated in Figuren As seen in Figure 3, the free `end of the shank lof the hook 23 is provided with a roundedportion 25 to permit 'said hook to swing upwardly with respect to the body inem ber A8 from its substantially straight, extended position of Figure 3, and has a substantially straight portion 26 disposed below the rounded upper portion 25 which abuts against the trans- Verse wall 13, when the hook 23 is disposed in an extended position relatively to the body i3, to prevent said hook 'from swinging downwardly beyond its extended position of Figure 3.

The side walls d, between the transverse wall I3 Aand the hook shank housing i2 are provided with corresponding, transversely 'aligned longitudinauy extending openings 2v each having three downwardly Veitending recesses forming upwardly opening notches `2S, 29 and 3B which open upwardly at Van incline and generally toward the hook shank housing i2. A hook 3l has its shank end 3'2 disposed between the side walls 9 and a pin 33 is secured therein, intermediate of its ends and has its 'end portions projecting laterally therefrom and through the openings 2l. The pin 33 is sized to slid'ably engage the openings 2'I and rotatably Iand detachably engage in any one of the notches 28, 2 and Sti. lThe hook 3| and the hook Ill are disposed to 'open toward Ione another, as clearly illustrated in Figures 1 and 3.

. direction and each of which is provided with a Ysubstantially straight shoulder 3% which faces in- Wardly of said undulating end or away from the notch 35 and a rounded opposite end or portion 39. The opposite end of the lever 3ft forms the handle 4t and may be of any desired length.

The chain tightening device l, previously described, is adapted to be used for connecting ends of a sprocket chain, a portion of which is illustrated in Figures 1 and 3 and designated 4l, for replacing the pin thereof or a link or for removing a link and tightening the chain, where said sprocket chain is trained over sprocket wheels or the like, not shown, and if it is desirable to repair or tightenthe chain without removing it from the sprocket wheels, in viewV ofthe difficulty of applying a properly sized chain to spaced sprocket wheels. For either repairing a break in the chain 4I or for tightening saidchain, the hook I4 is clamped relatively to the body 8 by swinging the lever i9 downwardly and into a depending position thereby displacingrthe eccentric por- Vtion ofthe cam 2t downwardly into bearing engagement with the clamping member i6 for swinging said member I6 downwardly on its pivot yI'I to clamp the hook shank I5 between'the member I6 and the bottom wall II. The hook I4 is then engaged with one pin 42 of the chain 4I, as illustrated in Figures 1 and 3 and adjacent a broken link thereof. The notch 35 of the lever 3d is then engaged with another link i2 of the chain on the other side of and spaced a considerable distancerfrom the break in the chain or the point where aA link Vis to` be removed to Vtighten the chain. Either the'notch 36 or the notch 3'! is then engaged with the hook portionV Mend the handle dd of the lever 3d is then grasped for swinging the lever 34 in a counterclockwise direction on the notch 35 with the pinY broken ends of the chain drawn together whenV pressure is released on the lever 34. This same result mayv be accomplished by positioning the pin 33 in engagement with the notches 28 and the hook 3i inrengagement with a' chain pin 42 before the broken ends of the chain are drawn together by movement of the lever 34 from its position of Figure l to its position of Figure 3,

Vin which oase, after the broken ends of the chain have been drawn together the shank end 32 of Y the hook 3l is displaced toward the shank I5 by moving the pin ends thereof from the notches 2S through the openings 2l into engagement with either the notches 25B or the notches Se and so Y that the broken chain ends will be held drawn together after pressureV on the lever 3d is removed. With the broken chain ends thus held to then disengage the chain tightening device l from the chain 4I, without again exerting pressure on the chain by use of the lever 34, it is only necessary to swing the lever I9 upwardly to displace the eccentric portion of the cam out of engagement with the clamping member I6 to thereby release the hook shank I5 from a clamped position so that it may be slid outwardly of the hook shank receiving housing I2 to enable the hook id to be disengaged from the chain pin i2 engaged thereby, after which the hook 3| may be readily removed from the chain and the lever 34 may obviously be readily disengaged.

Various modifications and changes are contemplated and may obviously be resorted to, without departing from the spirit or scope of the invention as hereinafter defined by the appended claims.

I claim as my invention:V

l. A sprocket chain tightening device comprising an elongated body member, a hook having Y a shank reciprocally disposed in one end of said drawn together by the hooks is and 3l, as illus--V body member for movement longitudinally thereof and projecting from said end, said hook being adapted to engage a sprocket chain pin on one side of a break therein or aV link thereof to be removed or repaired, a manually actuated cam means rotatably mounted in the body member, a clamp engaged by said cam means for clamping said hook shank in the body member in one position of said cam means, a hook pivotally connected to and projecting from the opposite end of said body member, a lever having longitudinally spaced notches adjacent one end thereof for selectively engaging said last mentionedhook and an oppositely spacing notch in the terminal of said end for engaging another-pin of the chain Von the other side of the link thereof to be resecond hookY as a fulcrum in a direction away from the body member, and a holding hook swingable mounted in the bodyrmember and extending Ydownwardly therefrom for engaging another pin of the chain and on the opposite side Y of the link thereof to be repaired or replaced from the pin engaged by the first mentioned'hookgsaid holding hook being longitudinally displaceable relatively to said body andV having means for retaining the holding hook in a plurality ofA selected longitudinally spaced positions for holding the spaced portions'of the chain after said portions have been drawn together by operation of the lever.

2.Y A chain tightening device as in claim l, said cani means being releasable for releasing the shank of the rst mentioned hook for disengaging the device from the tensioned sprocket chain.

3. A chain tightening device as in claim l, said body member having-parailel side walls provided with corresponding longitudinally extending elongated openings having longitudinally spaced up wardly opening notches defining the bottom portion thereof, and the shank end cf said holding hook having trunnions for slidably engaging said openings and for rotatably and detachably en-Y the notches for Vlcngitudinally displacing the holding hook relatively to the body member.

. e, A chainV tightening Ydevi-ce cc'niprisinganV elch ted body member, hook having its shank projecting from one endV thereof. and having a downturned bill portion for engaging a link of a sprocket chain, a fulerum member projecting from the opposite end of said body member, a pulling lever for swingably engaging said fulcrum lneniber near one end thereof and having a notch in said near end facing toward said hook for engaging another chain link, said lever being adapted to be manually operated or swinging it on the fulcrum member for displacing the notched end thereof toward said hook for drawing the chain links engaged by the hook and lever toward one another, and a holding hook swingably mounted in the intermediate portion of said body and longitudinally displaceable relatively thereto and having means for retaining it in a plurality of longitudinally adjusted positions, said holding hook being adapted to engage another link of the chain and facing the first mentioned hook for holding the links engaged by said hooks against movement away from one another after the chain has been tensioned by operation of the lever.

5. A chain tightening device as in claim 4, the shank of said first mentioned hook being slidably disposed in the body member and longitudinally thereof, and clamping means for releasably clamping the hook shank in the body member.

GOLDIE M. BURNETT.

No references cited. 

